(If you cannot see the horse, look at the red spot in the bottom centre of the picture.)

Computer chips are ridiculously complex, but prior to 1984 their layout was not protected by copyright or patent. So chip designers dropped unique miniature pictures into their work. They served as the equivalent of a little watermark: you could see right away if someone else had stolen your design because the image would show up as well.

That’s the official explanation for the appearance of art on computer chips. More likely is that chip designers are human, and when there’s a little space left over on a chip they want to put their own mark on the design and assert their own humanity. Which is a much better reason (in my books, at least).

Most of these pictures are so small that you’d need a strong microscope to even spot them. Fortunately, various websites collect images of clip art – and I’ve linked to the best one below. Chips contain Milhouse from The Simpsons, a Rolex watch, Snoopy, Groucho Marx, and Waldo of Where’s Waldo fame. My favourite: the Spirit and Opportunity Martian rovers actually contained image sensors with Marvin the Martian etched on them. So he got back to Mars after all.